lkml.org 
[lkml]   [2020]   [Mar]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [RFC PATCH 12/21] list: Poison ->next pointer for non-RCU deletion of 'hlist_nulls_node'
On Tue, Mar 24, 2020 at 03:36:34PM +0000, Will Deacon wrote:
> hlist_nulls_del() is used for non-RCU deletion of an 'hlist_nulls_node'
> and so we can safely poison the ->next pointer without having to worry
> about concurrent readers, just like we do for other non-RCU list
> deletion primitives
>
> Cc: Paul E. McKenney <paulmck@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Signed-off-by: Will Deacon <will@kernel.org>

Agreed, any code having difficulty with this change should use instead
hlist_nulls_del_rcu().

Reviewed-by: Paul E. McKenney <paulmck@kernel.org>

> ---
> include/linux/list_nulls.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/include/linux/list_nulls.h b/include/linux/list_nulls.h
> index fd154ceb5b0d..48f33ae16381 100644
> --- a/include/linux/list_nulls.h
> +++ b/include/linux/list_nulls.h
> @@ -99,6 +99,7 @@ static inline void __hlist_nulls_del(struct hlist_nulls_node *n)
> static inline void hlist_nulls_del(struct hlist_nulls_node *n)
> {
> __hlist_nulls_del(n);
> + n->next = LIST_POISON1;
> n->pprev = LIST_POISON2;
> }
>
> --
> 2.20.1
>

\
 
 \ /
  Last update: 2020-03-31 01:33    [W:0.178 / U:0.432 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site